Various kinds of endoscopes are commonly used for examination and treatment within a patient's body cavity. Endoscopes generally have a tubular portion which is inserted into a patient's body cavity and a handle portion which remains outside the patient to be manipulated by a physician. The tubular portion typically carries a fiberoptic viewing bundle which cooperates with an eyepiece in the handle portion to permit viewing within the body cavity. The spacing between the end of the viewing bundle and the eyepiece must be exact for proper focus. A single optical fiber is usually also provided for illumination. Typical of such endoscopic devices are U.S. Pat. Nos. 4,146,019 to Bass et al., 4,163,148 to Fritsche et al., and 3,818,902 to Kinoshita et al.
All of these endoscopic devices suffer from the same drawback. The tubular portion of the device which carries the fiberoptic viewing bundle is fixed on the handle portion. The entire endoscopic device must be sterilized before the tubular portion can be inserted into a patient. Because of the sensitive nature of the optics carried by the eyepiece, steam sterilization and immersion is not possible and ethylene oxide gas is usually used. This requires a longer sterilization time making the entire instrument unavailable for use during this time.
Having the tubular portion fixed on the handle portion has another disadvantage. Viewing bundles and optical fibers are rather delicate and the tubular portion is usually bent as it is inserted into the patient. This places substantial tension and compression forces on the bundle and fibers. After a substantial amount of use, many of the individual fibers making up the viewing bundle begin to break, obstructing viewing. Similarly, a single optical fiber as used for illumination can also break, preventing its use.
Eventually the viewing bundle or optical fiber must be replaced. However, since they are fixed along their entire length within the tubular portion, removal from the tubular portion is difficult if not impossible. The tubular portion in turn is fixed on the handle portion to provide the proper spacing between the bundle end and the eyepiece. This makes replacement of a bundle even more difficult. Often, the entire device is disposed of, or requires factory service.
Many endoscopes also include one or more channels for introducing a flushing liquid into the patient's body cavity. These flushing channels communicate with connectors mounted on the handle portion of the device adjacent the eyepiece. When there is any leakage of liquid from these channels or connectors on the handle portion, the optical system in the eyepiece can be damaged, if not destroyed.
Another common problem with present endoscopes is that rotation of the handle portion also causes rotation of the tubular portion. Movement of the handle portion may be inadvertant or to provide a better grip for the physician. Rotation of the tubular portion in a body lumen can damage the lumen and move the end of the endoscope away from the tissue being studied.
It is also desirable to photograph the image seen through the endoscope to provide a record and allow for further study. The present devices are generally adapters which mount a camera on the existing eyepiece. Unfortunately, this is a rather bulky combination that can be difficult to handle. Placing an adapter on the existing eyepiece also adds additional lenses which further reduces the light transmission through the entire combination. This can limit the photography that is possible depending on the lighting conditions.
Accordingly, what is needed is an endoscopic device which allows for relatively easy replacement of a viewing conduit or optical fiber which may be damaged through use. That portion of the device which comes in contact with the patient should be separately sterilizable to avoid damage to eyepiece optics. The endoscopic device should also separate any fluid channels from the eyepiece optics to avoid damage from leakage and for ease of use. In addition, the device should minimize breakage of optical fibers from flexing and bending of the tubular portion of the device and permit rotation of the handle portion without moving the tubular portion. The present invention meets these desires.